It was the charger under the backseat. It had a "thermal incident" and is being replaced under warranty.

Phew!! So happy I wasn't going crazy and imagining it.

I'm having very similar issues. 2011 LEAF SLV with 55,617 miles. Got a new traction battery a few months ago under warranty (yay!) and a few weeks ago began smelling an ozone like smell in the car in the morning after a normal midnight to five am charge cycle. Didn't smell exactly like burning or "magic smoke", but definitely had an arcing "slot-car" or "bumper car" like smell.

I have a TOU meter from San Diego Gouge & Extortion for the car and have set the car's timer to kick on just after midnight and shut off at five during the least usurious TOU rates. I also noticed that about that same time that when I plug in the charging cord on the Blink L2 EVSE when I get home the car no longer "handshakes" with the EVSE as it had done for years. It still appears to be charging normally, but the car only shows the rotating flashing lights (indicating plugged in, waiting for charge timer to initiate charging) when queried from the phone app (which appears to "wake the car up"). The smell has gotten "better" and is now almost all but gone, but I fear I may have a similar problem as described here earlier in this thread. I'm working on getting a hold of my dealer's "LEAF specialist" to see about having this checked out.

I am very grateful for those of you who have contributed to the overall knowledge base on this site!

getting this smell the last few days on my 2011 LEAF (one of the very first).. concerned because it is out of warranty and the smell is very strong. Smell occurred after charging on a brand new chargepoint charger at work. I'll contact Nissan Service.